1. Field of the Invention
The present invention relates to television camera devices installed at automatic cash payment devices in counters of stores and banks.
2. Description of the Prior Art
Conventionally, when a television camera of this type is installed at an automatic cash payment device in a bank or the like so that its single image pickup camera monitors a wide range at a time, the image pickup camera is mounted on a rotational stand, which is rotated at predetermined intervals of time.
At this time, since the brightness of an object, the image of which is to be picked up, fluctuates due to rotation of the camera, it is necessary to cause control the iris of the lens or the shutter speed in accordance with a change in a quantity of light from the object. To this end, the indoor quantity of light is devised so as to be as uniform as possible or a lens is used which has the function of automatically adjusting the quantity of light to thereby cause the iris of the lens to automatically follow a possible change in the quantity of light of the object.
In the conventional television camera devices, the quantity of light of the overall object is automatically adjusted and the iris of the lens is adjusted to the quantity of light. However, if the object to be imaged simultaneously includes a window through which external light is received and a person to be monitored, the iris of the lens must be adjusted to the person to be monitored (hereinafter referred to as a moving object). However, this adjustment is influenced by objects, such as a landscape, which can be viewed through the window in addition to the person (hereinafter referred to as a fixed object). If the iris of the lens is adjusted in accordance with such an object, with reference to automatic light quantity adjustment, the iris would be adjusted to the window through which external light is received. Thus, an image picked up of the face of a person who is the moving object would be undesirably dark.
Also, when the light sensitive time of the image pickup camera is changed in accordance with a change in the shutter speed of the camera under the above image pickup conditions to thereby make light quantity adjustment, the shutter speed would be adjusted to the window through which the external light is received and the picked up image of the face of the person who is the moving object would be undesirably dark.
During the operation of the stand, the video signal would flow asynchronously and undesirably the object would not be clearly determined.